package com.jingdianjichi.subject.domain.util;

import com.alibaba.fastjson.JSON;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;

import javax.swing.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.function.Function;

/**
 * 缓存工具类
 */
@Component
public class CacheUtil<K,V> {

    private Cache<String,String> localCache =
            CacheBuilder.newBuilder()
                    .maximumSize(5000)
                    .expireAfterWrite(10, TimeUnit.SECONDS)
                    .build();


    /**
     * V 类型 SubjectCategoryBO
     * @param cacheKey  cacheKey
     * @param clazz  序列化的类型 JSON.toJSONString(subjectCategoryBOS)
     * @param function String K   function getSubjectCategoryBOS()
     * @return
     *
     * cacheKey实际是String cacheKey = "categoryAndLabel." + subjectCategoryBO.getId();
     * 也是key  但是 (key) -> getSubjectCategoryBOS(id)没有使用这个key
     */
    public List<V> getResult(String cacheKey , Class<V> clazz,
                             Function<String,List<V>> function){
        List<V> resultList = new ArrayList<>();
        String content = localCache.getIfPresent(cacheKey);
        if (StringUtils.isNotBlank(content)){
            resultList  = JSON.parseArray(content,clazz);
        }else {
            resultList = function.apply(cacheKey);//此处的cacheKey是 SubjectCategoryDomainServiceImpl getSubjectCategoryBOS(id)的id
        }
        if (!CollectionUtils.isEmpty(resultList)){
            localCache.put(cacheKey,JSON.toJSONString(resultList));
        }
        return resultList;
    }


    public Map<K,V> getMapResult(String cacheKey , Class<V> clazz,
                         Function<String,Map<K,V>> function){

        return new HashMap<>();
    }
}
